Renewable cutter underreamer



, Jan. 14,1930. J. GRANT ETAL 1,743,769

RENEWABLE CUTTER UNDERREAMER Filed May 12. 1925 2 sheets-sheet 1 INVENTOR. /0/70 Gran) ATTORNEYS.

Jan'.14,1930. V J. GRANT ET m. 1,743,769

RENEWABLE CUTTER UNDERREAMER .Filed May 12, 1926 2 Sheets-Sheet 2 INVENTOR. Job/7 Gray/7f y Warm/fl. (0/77 fid/ mzzawfl I ATTORNEYS.

Patented Jan. 14, 1930 UNITED STATES PATENT OFFICE.

JOHN GRANT, OF LOS ANGELES, AND STEWART L. CAMPBELL, OF BERKELEY, GALL FORNIA; SAID CAMPBELL ASSIGNOR TO SAID GRANT RENEWABLE CUTTER UNDERREAMER Application filed May 12,

This invention relates to an underreamer having a plurality of cutters, some of which are maintained in idle position while others are in working position and whereby the idle and working cutters may be interchanged atwill without the withdrawal of the tool from the hole.

It is the primary object of this invention to. provide a tool of the character described having interchangeable cutters movable from idle to work position. and vice verse. by movement of the tool into and out of the well casing. Another object of thisinvention is to provide an expansible underreamer collapsible by engagement of the cutters with the well casing and which upon expansion subsequent to the collapsion will present an other set of cutters in working position. A further object of this invention is to provide a fish tail bit for the tool having a' replaceable blade of novel construction. A still further object of this invention is first, to provide a tool having advancing means operating auto matically within certain limits, and second to provide means therefor indicating the full expansion of the advancing means.

These objectstogether with other objects and corresponding accomplishments are obtained by means of the embodiment of our invention illustrated in the accompanying drawing, in which:

Fig. 1 is a front elevation of a complete tool; Fig. 2 is a side elevation partly in section of a fragment of the tool shown in Fig. 1; Fig. 3 is a section as seen on the line 3-3 of Fig. 1; Fig. i is a section as seen on the line 44 of Fig. 1; Fig. 5 is an axial section through the shank end of the tool showing the advancing means; Figs. 6, 7, and 8 are sections as seen on the lines indicated by the cor-N responding numbers in Fig. 5.

Referring more particularly to Fig. 1, the tool comprises three parts. One part is the shank indicated by A, another the underreamer part indicated by B, and at the bottom is the boring part indicated by C. A

Referring more particularly to the underreamer portion of the tool, it comprises a body 10 of substantially cylindrical form having a tapered threaded pin at its upper 1926. Serial N0. 108,520.

an axially extending front face 141 which is in line with the inclined portion of the ramp 13 and disposed rearward of the axial face 13 of bottom ramp 13. 7

Slidably and rot-atably disposed within each chamber is a" cutter carriercomprising a body 15 with radial extensions 16, 17 and 18. The cutter carrier is mounted on pintles 19 and 20 rotatably'and longitudinally slidably mounted in corresponding bearing openings in the body. The chamber 11 is of such length that the carrier may have a limited longitudinal movement. A compression spring 21 urges the carrier into its upper position as shown in Figs. 1, 2, and i.

V'Vhen a carrier is in its upper position, one of the cutters will be in projected or expanded position, by reason of one of the extensions projecting beyond the outer surface of the body. lVorking movementofthe tool is in I the direction indicated by the arrow in Fi 3. The ramp '12 holds and maintainstlie cutter projected as the resistance issuch as to force the cutter against the face 1 1 of the ramp. If the tool is withdrawn into a casing, the projecting cutters will be engaged by by the lower end or shoe of the casing. Continued movement causes the carriers to be moved downwardly against the action of springs 21, the lower edge ofthe projected cutters engaging the inclined upper faces of ramps 13. Continued relative downward movement of the carriers will cause them to be turned by reason of the wings sliding downwardly and rearwardly upon the ramps 13. In their lower position, the cutters are sheltered within the chambers. Upon re.- lease of the pressure upon the upper edges of the carriers, springs 21 ur e the carriers upwardly, and the previously orojected cutters move upwardly against the inclined faces of ramps 12, progressively turning the carriers so as to present the succeeding cutters. It is obvious that a new cutter may be presented in working position by drawing the tool into the casing and then lowering the same. By having blade and roller cutters, it is possible to change from a blade cutter to a roller cutstructure. I

The boring portion of the tool indicated by G is of the fishtail type with a replaceable blade. This is convenient in. order to construct the blade of a different materialthan the body. The bit comprises a blade portion 22 having a tenon 23 ending in a cylindrical portion 24. The construction is arranged to lit into a corresponding transverse groove in the body to provide a dovetail connection. The lower end of the body has tapering faces 25 against which wings 26 of the blade may engage.- To securely hold the blade in position, rivets 27 extending through the body and shank may be provided. It is obvious that a new blade may be inserted in position ter or'vice versa as will be apparent from the by removing the rivets and slipping the blade sideways out of the groove.

Referring more particularly to the shank A it comprises a cage 28 having a threaded tapered socket at the lower end and a threaded pin at the upper end. The cage is provided with achamber 29. within which is mounted a washer 30. Above the washer is a spring 31 and below the washer is a smaller compression spring 32 which is disposed partially in a chamber 33. Slidablymounted within the chamber 33 is a head 34; of a plunger having a stem 35. The chamber 33 is square in cross section and the head 34 is of a corresponding shape; The stem35 is also square and extends through'the bottom of the cage, being provided with socket end 36 to receive the tapered pin on the body 10. A bore 37 extends through the upper portion of the cage and communicates with the chamber 29. The washer 30 has ports 38 at its edges to permit circulation fluid to pass therearound v ien the washer is above and out of engagement with shoulder 39. The plunger is also provided with a circulation passage 40 communicating with the chum er 33. Thus, circulation water may pass through a central passage 41 in the body and through ducts 42 so as to provide the cutting blades with circulation water. When the washer 30 is in its lower position resting upon ledge 39, ports 38 are closed and the flow of circulation water is stopped. This would cause stalling of the circulation pump. and is availed of as a means to indicate the full expansion of the shank.

In operation of the tool, the carriers are pressed downwardly and the cutters collapsed into idle position so they may be introduced into the casing. The tool is then lowered, and

as it leaves the bottom of the casing, the springs urge the carriers upwardly, a cutter engaging the upper ramp and turning the carrier to project the next cutter. The tool being forced downwardly, will cause compressionof the springs in the shank and contraction thereof. This places the tool in such condition that it isbeing constantly urged forward with a. yielding pressure. This avoids the tool grabbing and advance will continue until the shank has fully expanded whereupon the washer 30 is positioned to stop the circulation and indicate that the tool unit should be advanced to cause contraction of the shank. To change cutters, the tool is elevated until the carriers strike the bottom of the casing. Further movement will slide the carriers downwardly the projecting cutter engaging the lower ramp and turningthe carriers to idle position of all of the cutters.

What We claim is:

1. A tool of the character described com prising a body havinga chamber, a cutter carrier disposed in said chamber and mounted on said body to swing about an axis extend ing lengthwise of said body, said carrier having a plurality of cutters laterally disposed whereby one of said cutters maybe maintained to project beyond said body in working position while the remaining cut ters will be disposed within said body in idle posit on, and means operative by virtue of longitudinal movement relative to the carrier to swing said carrier so as to retract a cutter from working position and project a cutter from idle; position.

2. A tool of the character described comprising a body having a chamber, a cutter carrier mounted for rotation and longitudinally slidable movement about an axis extend.

ing lengthwise of said body, said carrier havmg a plurality of cutters laterally d1sposed whereby one of said cutters may project beyond said body in working position and the,

remaining cutters will be disposed within said body in idle position, and cam means on the body adapted, on longitudinal movementof the carrier, to rotate the carrier to retract acutter from projected position and to project another cutter beyond the body.

3. A tool of the character described comprising a body having a chamber, a cutter carrier. mounted for rotation and longitudinally slidable movement about an axis extending lengthwise of said body, said carrier having a plurality of cutters laterally disposed whereby one of said cutters may project beyond said body in working position and the remaining cutters will be disposed within said body in idle position, said body having a ramp depending at the rearupper corner of the opening of said chamber, said ramp being arranged to serve as an abutment to maintain the working cutter in projected position, a lower ramp at said opening forward of the first mentioned ramp and having its inclined face directed oppositely, whereby movement of a cutter over said ramps turn said carrier and resilient means tending to maintain said carrier in its upper position.

4. A tool of the character described, comprising a body, a plurality of cutters transversely movable thereon to and from laterally projected and retracted positions, connective means between the cutters whereby one is projected transversely when another is retracted transversely, and means operable by longitudinal movement relative to the cutters to cause their transverse movement.

5. A tool of the character described comprising. a body, a plurality of cutters transversely movable thereon to and from laterally -projected and retracted positions and also longitudinally movable thereon, connective means between the cutters whereby one is projected transversely when another is retracted transversely, and means on the body adapted to cause transverse movement of a cutter by virtue of its longitudinal movement.

6. A tool of the character described, comprising a body, a plurality of cutters rotatable on a longitudinal axis eccentric of the body center and adapted by rotation on the axis to swing laterally to and from relatively projected and retracted positions, connective means between the cutters whereby one is proj ected when the other is retracted, and means operable by longitudinal movement relative to the cutters to cause their rotation.

7. A tool of the character described, comprising a body, a plurality of cutters rotatable and longitudinally movable on a longitudinal axis eccentric of the body center and adapted by rotation on the axis to swing laterally to and from relatively projected and retracted positions, connective means between the cutters whereby one is projected when the other is retracted, and means on the body adapted to cause rotation of a cutter by virtue of its longitudinal movement.

8. A tool of the character described, com prising a body, a plurality of cutters transversely movable thereon to and from laterally projected and retracted positions, connective means between the cutters whereby one is projected transversely as another is retracted, means operable by longitudinal movement in one direction relative to the cutters to cause their partial transverse movement from one position toward the other, and means oper able by longitudinal movement in the other direction relative to the cutters to cause completion of their transverse movement.

9. A tool of the character described, comprising a body, a rotatable cutter carrier mounted in the body on a longitudinal axis eccentric of the body center, cutters spaced circumferentially around the carrier, the carrier and cutters being so arranged that by romoved successively to a position projected from the body, and means operable by longitudinal movement relative to the carrier and cutters to rotate them from a position in which one cutter is projected to a position in which another cutter is projected.

10. A tooloit' the character described, comprising a body, a rotatable cutter carrier mounted in the bodyon a longitudinal axis eccentric of the'body center, cutters spaced circumferentially around the carrier, the carrier and cutters being so arranged that by rotation of the carrier the several cutters may be moved successively to a position projected from the body, means operable by longitudinal movement in one direction relative to the carrier and cutters to rotate them through a part of the circumferential distance between adjacent cutters,-and'means operable by relative longitudinal movement in the opposite direction to rotate the carrier and cutters the remaining distance between adjacent cutters.

1 11. A tool of the character described, comprising a body, acutter carrier mounted in the body to rotate and move longitudinally on alongitudinalaxis eccentric of the body center, cutters spaced circumferentially around I the carrier,the carrier and cuttersbeing so arrangedthatbyrotation of the carrier the several cutters may be moved successlvely to a position projected from the body, a cam on the body adapted to engage a cutter on longitudinal movement of the carrier and cutters in one direction torotate them through a part of the circumferential distance between adjacent cutters, and another cam on the body adapted toengagea cutter on longitudinal movement in the opposite direction to rotate the carrier and cutters through the remaining distance between adjacent cutters.

12. In an expansive reamer, a body, a cutter carrier mounted on the body for rotation on an axis eccentric of the body, a plurality of cutters mounted in circumferentially spaced relation about the carrier and adapted by rotation of the carrier to be moved successively to a position projecting beyond the body, and means on the body stopping each cutter in projected position and supporting it against torsional stresses.

13. In an expansive reamer, a body, a cutter carrier mounted on the body for rotation on an axis eccentric of the body, a plurality of cutters mounted in circumferentially spaced relation about the carrier and adapted by rotation of the carrier to be moved successively to a position projecting beyond the body, means on the body stopping each cutter in projected position and supporting it against torsional stresses, means for causing rotation of a cutter away from the stopping means and rotating the cutter and carriers through a circumferential distance approximately half the circumferential distance beion , tween cutters tobring the next cutter-up tween carriers, 'and further fmeans to cause rotation of the carrier and cutters through the remamderot the circumferentlal'dlstance beagainst the stopping means.

14. In an expansive reamer, a body, a cutter carrier mounted for rotation in the body and carrying a plurality of cutting edges adapted by rotation of the carrier to be successively projected beyond the; body, and means to support the holder and its-cutting edges against torsional stresses with a cutting edge projecting beyond thebody.

15. In an expansive reamer, a body, a cut ter carrier mounted on the body for rotation on an axis eccentric of the body,a cutter mounted on the cutter carrier and projecting therefrom and adapted 1n one rotative position to project beyond the body, stop means to stop and hold the carrier and cutter in cutter projecting position and to support the cutter against rotation in one direction, and meanswhereby the cutter and carrier are disengaged from said stop means and rotated on in said direction to a positionbeyond the pr'oe jecting position of the cutter. r

16. In an expansive reamer, a body, a cutter mounted in the body fonlongitudinal movement along and transverse swinging motion about a longitudinal axis and adaptedln one swinging position to project beyond the body, means acting by virtue of longitudinal movementof the cutter in one'directionto swing it in a certain'rotational direction to ,itsprojected position, and means acting by virtue of longitudinal movement'in the opposite direction to swing thecutter on in the same rotational direction away from its projected position. r g a j In Witness-that I claim the foregoing I have hereunto subscribed my name thislst day of May, 1926. V

. JOHN GRANT.

In Witness that I claim the foregoing I have hereunto subscribed my name this 5th day of May, 1926.

STEWART L. CAMPBELL.- 

